It appears to me that you are assuming far more than I am; I never made those statements, nor do I believe them all. However, I have never seen termites attack above grade components of a deck constructed with the PROPER GRADE of treated lumber. Then again, I've only been doing this 9 years and I haven't seen it all. And if your deck isn't made of lumber resistant to WDI activity, you have potentially bigger problems that can't be solved by removing a little cardboard that may exist. And if this is the case, you better be monitoring it for activity since it's all but a given that it will occur.

I certainly never said that debris around structures was not conducive to WDI activity; in fact, I tell folks to move firewood stacks away from their foundations all the time. I also frequently write up old batter boards and debris in crawlspaces. Unfortunately, most homes around here are not on concrete slabs so I write this up a lot.

In simple terms, it's a matter of both visibility and relative risk in my opinion. If you have a post sitting on an above grade poured concrete pier of what should be a significantly larger diameter, (oops, there I go making an assumption) there will be some exposed concrete around the base of the post. Termites would have to cross this exposed area to get to any wood, and they would have to do this whether the form is still in place or not. In an open environment, I find it hard to believe that they could do this without being seen. So even if the form lets them get to the top of the pier unobserved, they face the same obstacle of getting from there to the wood. Again, that is the same whether there is a form in place or not. So if there is no form in place above grade, and they build tunnels up the outside of the pier -- and we both know they are perfectly capable of doing this -- they could still get into the deck just the same if no one is watching for them.

Ultimately, I don't see how a form makes much difference. If you are vigilant regarding termites they will be visible at a point before they get into the wood -- regardless of exactly how they get to the top of the pier. If you aren't paying attention you stand the chance of problems with or without forms since they can come up the outside of the pier.